Fuse-link



ec, BL 1935.. R. R. PITTMAN ET AL.

FUSE LINK Original Filed Sept. 29, 1953 Fly 2 Fzy. J 50 I BY M 6 ATTORNEY Patented Dec. 31, 1935 UNITED STATES antes!) @FiCE FUSE-LINK Ralph E. Pittman and Carroll H. Walsh, Pine Blufi, Ark.

' flriginai application September 29, 1933, Serial No 691,496, new Patent No. 1,965,391, dated j 8, i934. Divided and this application No- This invention relates generally to protective devices for electrical circuits, and particularly to fusible devices used to prevent the passage of excessive currents through said circuits.

Many circuit-interrupting devices depend for their operation upon a tensioned fuse-link, with the result that such links are normally continuously under tension. Such stress is undesirable on the fusible element of the fuse-link, especially in the lower amperage sizes, as it may cause the link to fail mechanically after a certain period of time.

The present application is a division of our prior application Serial No. 691,496, filed Sept. 29, 1933, now Patent No. 1,965,391, issued July 3, 1934, in which we have claimed a fusible circuit-interrupting device for which the fuselink herein described is suitable. The claims of the present application are directed to the fuse- 2 link disclosed in the aboveentioned application.

-An object of the present invention is the provision of a novel fuse-link for use generally in fusible circuit-interrupting devices, so arranged that the fusible element of the fuse-link is relieved of all tension tending to pull it apart.

A further object is to provide a simple, inexpensive and efiective device for the purpose described.

30 With the above and other objects in view which will appear as the description proceeds, our invention resides in the novel construction, combination and arrangement of parts as hereinafter described and more particularly defined in the appended claims, it being understood that such changes as come within the scope of the claims may be made in the embodiment herein disclosed.

In the drawing:

40 Figure 1 is a side elevational view of the fuse-link, illustrating the assembly 35.

Figure 2 is a fragmentary side elevational view of the upper portion of the fuse-link.

Figure 3 is a fragmentary front elevational 45 View of the upper portion of the fuse-link.

Figure 4: is a sectional view of the fuse-link as seen from the plane indicated by the line IVIV in Figure 2.

Referring in detail to the above-mentioned 50 figures, 55 and 29 represent the usual conductors employed in fuse-links generally, the latter member being provided in the usual manner with a terminal-engaging button 59. The adjacent ends of the members 49 and 55 are pro- 55 vided with slots extending laterally therethrough,

and a flexible loop of suitable insulating material, such as cellulcid, mica, cambric or fiber, extends through the slots and between the memhere 59 and 55. The fusible element 5!, preferably of some alloy melting at a relatively low temperature as compared to an unalloyed metal, extends through the loops of insulating material on the side of the members 39 and 55 opposite the connecting insulating member, and electrically connects the members. A small amount of slack is preferably left in the fusible eiement betwee the ends of the members 59 so that any tension applied to the fuselink is impressed upon the flexible insulating material 52 instead of the fusible element 5i; 15 the latter being only in compression within the loops. It will be seen that that portion of the fusible element 5i enclosed within the loops of insulating material will be at the highest temperature, since the radiation of heat due to the current through this portion of the element is restricted; therefore this portion of the element is the first to melt. The are following the melting of the fusible element 5% may destroy the loop of insulating material by burn- 5 ing it, or, if the material of the loops is not inflammable, may vaporize or melt the portion of the element within the loop; either of these occurrences allowing the member 55 to move away from the member 39.

What we claim as our invention is:

l. A fuse-link adapted for installation in an expulsion fuse, comprising two conducting members, one end of one conducting member being adjacent but spaced from one end of the other conducting member, a slot adjacent the adjacent ends of said conducting members, a closed loop of flexible insulating material extending through said slots and mechanically connecting said conducting members, and a fusible element extending through said closed loops and electrically connecting said conducting members.

2. A fuse-link adapted for installation in an expulsion fuse, comprising two axially spaced conducting members, an opening extending transversely through each of said members adjacent the contiguous ends thereof, a closed loop of flexible insulating material extending through each of said openings and mechanically connecting the contiguous ends of said members, and a fusible element extending through said closed loops and electrically connecting said members, the remote ends of said members being adapted for connection to the terminals of an expulsion fuse housing.

3. A fuse-link adapted for installation in a fuse housing, comprising two axially spaced conducting members, an element of insulating material and a fusible element, said fusible element electrically connecting the contiguous ends of said conducting members and mechanically co-operating with said element of insulating material for mechanically connecting said conducting members.

4. A fuse link comprising two axially spaced conducting members, a fusible element, and an element of insulating material, said fusible element cocperating with said insulating material to mechanically connect said conducting members.

5. A fuse link comprising two axially spaced conducting members, a fusible element, and an element of insulating material, said fusible element cooperating with said element of insulating material to mechanically connect said conducting members, and means responsive to the fusing of said fusible element for mechanically breaking the mechanical connection.

6. In a fuse link, longitudinally spaced conducting members, a fusible element electrically connecting said conducting members, and an element of insulating material, the cooperation between said fusible element and said element of insulating material with said conducting members being such as to mechanically join the contiguous ends of said conducting members.

RALPH R. PITTMAN. CARROLL I-I. WALSH. 

